Best practice for getting datatype size(sizeof) in Java
See @Frank Kusters’ answer, below! (My original answer here was for Java versions < 8.)
sizeof
Size of a byte array golang
To return the number of bytes in a byte slice use the len function: bs := make([]byte, 1000) sz := len(bs) // sz == 1000 If you mean the number of bytes in the underlying array use cap instead: bs := make([]byte, 1000, 2000) sz := cap(bs) // sz == 2000 A byte is guaranteed … Read more
Is “sizeof new int;” undefined behavior?
The warning doesn’t state that it’s UB; it merely says that the context of use, namely sizeof, won’t trigger the side effects (which in case of new is allocating memory). [expr.sizeof] The sizeof operator yields the number of bytes occupied by a non-potentially-overlapping object of the type of its operand. The operand is either an … Read more
C vs C++ sizeof [duplicate]
In C, a struct definition like struct x { int a; int b; }; does not define a type x, it defines a type struct x. So if you remove the int x; global, you’ll find the C version does not compile.
Is there a bit-equivalent of sizeof() in C?
You cannot determine the size of bit-fields in C. You can, however, find out the size in bits of other types by using the value of CHAR_BIT, found in <limits.h>. The size in bits is simply CHAR_BIT * sizeof(type). Do not assume that a C byte is an octet, it is at least 8 bit. … Read more
Why is sizeof(bool) not defined to be one by the C++ standard?
The other likely size for it is that of int, being the “efficient” integer type for the platform. On architectures where it makes any difference whether the implementation chooses 1 or sizeof(int) there could be a trade-off between size (but if you’re happy to waste 7 bits per bool, why shouldn’t you be happy to … Read more
How to get the string size in bytes?
You can use strlen. Size is determined by the terminating null-character, so passed string should be valid. If you want to get size of memory buffer, that contains your string, and you have pointer to it: If it is dynamic array(created with malloc), it is impossible to get it size, since compiler doesn’t know what … Read more
Difference between sizeof(empty struct) and sizeof(struct with empty array)?
In C, the behavior of a program is undefined if a struct is defined without any named member. C11-ยง6.7.2.1: If the struct-declaration-list does not contain any named members, either directly or via an anonymous structure or anonymous union, the behavior is undefined. GCC allows an empty struct as an extension and its size will be … Read more
Size of int and sizeof int pointer on a 64 bit machine
No, the sizeof(int) is implementation defined, and is usually 4 bytes. On the other hand, in order to address more than 4GB of memory (that 32bit systems can do), you need your pointers to be 8 bytes wide. int* just holds the address to “somewhere in memory”, and you can’t address more than 4GB of … Read more
What does sizeof(&array) return?
Difference between &str and str, when str is declared as char str[10]? Read sizeof Operator: 6.5.3.4 The sizeof operator, 1125: When you apply the sizeof operator to an array type, the result is the total number of bytes in the array. So, according to your declaration, sizeof(str2) gives the complete array size that is 10 … Read more